In numerous mass-produced calibres, the balance spring stud, forming the external point of attachment of the balance spring, is clipped to a stud-holder, which is a flat, stamped part.
In high end productions, the balance spring stud is screwed into a stud-holder which is a machined component. The retaining screw then works between the foot and threads of the screw. The head is never locked, which causes frequent breakage, as a result of the torsion stresses experienced when the foot is locked onto the balance spring stud and when the operator continues to turn the screw.
DE Utility Model No 202010024253 in the name of DAMASKO describes a balance spring stud with radial adjustment relative to the balance cock. The axially threaded stud cooperates with a cylindrical screw, whose head moves in a milled oblong groove.
EP Patent Application No 2290477A1 in the name of GLASHÜTTE UHRENBETRIEB describes a stud-holder which includes an internal thread for securing the stud retaining screw, which cooperates with a recess in said stud, over one part of the thickness of the stud.